Create 3.longest-substring-without-repeating-characters.py

Solution in py

Author: rachitiitr

LeetCode/3.longest-substring-without-repeating-characters.py

@@ -0,0 +1,26 @@
+class Solution {
+public:
+    int lengthOfLongestSubstring(string s) {
+        if(s.size()==0)return 0; // did you handle this?
+        int n = s.size();
+        int i(0), j(0);
+        
+        // s[j] is a char, 'A' is 65, 'a' is 97
+        vector<int> cnt(300, 0); // ASCII length of 255 will be fine
+        cnt[s[0]]++; // this can crash if string is empty
+        
+        int ans=1;
+        while(j!=n-1){
+            if(cnt[s[j+1]] == 0) {
+                j++;
+                cnt[s[j]] = 1;
+                ans = max(ans, j-i+1);
+            }
+            else {
+                i++;
+                cnt[s[i]]--;
+            }
+        }
+        return ans;
+    }
+};